Marga Hoogendoorn

36 Validity of the quantif ication of the nursing time needed The way in which the workload systems quantify the needed nursing time and the validity of this quantification is described in table 3. The most common way is classification of care into different categories of Nurse:Patient-ratios. Any evaluation of the validity of these categories of Nurse:Patient-ratios was described for 15 out of 27 systems (56%). In three cases (11%) the number of nurses needed according to the calculatedNurse:Patient- ratio was compared with actual time measurements. The calculated need for nursing staff according to TISS or PINI was higher than the measured nursing time 42, 46 . Comparing the Nurse:Patient-ratio according to the NWL Patient Category Scoring System with the observed time-measurements, showed substantial differences. The time spent with a patient in the category with an expected Nurse:Patient-ratio of 0.5:1 was more than the time spent with a patient in the category with an expected Nurse:Patient-ratio of 1:1. The researchers concluded that the categorization according the NWL Patient Category Scoring System was not accurate 34 . In five systems (19%) the translation of scores into a N:P-ratio was evaluated by comparing different systems applied to the same patients. A good agreement was reported between the Nurse:Patient-ratio according to the TISS and NEMS; which is not surprising because the NEMS was developed based on the TISS 46 . The need for nursing staff according to TOSS was up to 52% higher than with TISS. Where TISS indicated a Nurse:Patient-ratio of 2:1 TOSS indicated in the same patient a Nurse:Patient-ratio of 3:1 22 . Also in ICNSS the need for nurses was higher than in TISS for the same patients 69 . The need for nurses according to NAS was higher than the need for nurses according to NEMS 65 . Table 3 shows a retrospective comparison of the Nurse:Patient-ratio with the actual or planned number of nurses in 11 systems (41%) 18, 23, 30, 40, 52, 57, 60, 82-84 . The ‘midnight census’ on planning the actual number of nurses per unit was also described as a method for classification of care 40, 85 . For five systems it was concluded that the need for nurses according to the system was higher than the actual present staff 18, 22, 34, 42, 83 . However, none of these articles mentioned how the actual or planned number of nurses was calculated and on which assumptions these numbers were based.